SANAA, Yemen — Security and hospital officials say around 100 people have been injured after supporters of Yemen’s embattled leader fired in the air to celebrate the reportedly successful surgery he underwent in Saudi Arabia.

The gunfire appeared to be a show of force by President Ali Abdullah Saleh’s supporters.

The officials also say at least 40 private cars were damaged from the gunfire early Thursday.

The wounded included 20 people from a Sanaa square that has been the epicenter of protests demanding Saleh’s ouster.

The officials spoke on condition of anonymity because they were not authorized to speak to the media.

Saleh underwent surgery Monday to remove shards of wood from his chest and treat burns on his face and chest from an attack on his Sanaa compound.